From the Book

Leading (pronounced “ledding”) is the space between lines of type. The term comes from the days of hot-metal typesetting when thin strips of lead, known as reglets, were inserted by hand between the lines of type to add vertical space. Lines of type without these strips of lead were—and still are—referred to as “set solid.” Leading plays a big part in the readability of text. Body text is usually made more readable by a positive amount of leading (a value greater than the point size of the type). Headlines and display type, however, may benefit from negative leading. When it comes to screen type, leading is usually referred to as line height.

Getting the Lead Out

When it comes to leading there’s no “one size fits all.” Tight leading increases the density of the type and gives it authority. But if you go too tight, your type looks claustrophobic and the descenders of one line collide with the ascenders of the next. Loose leading can create a luxurious look. But if it’s too loose, the lines of type look like individual strips rather than cohesive paragraphs and the type is made less readable. This is especially true if the leading value is greater than the size of the space between the paragraphs.

The positive leading is indicated here in red. The total leading is measured from the baseline of one line to the baseline of the next.

Leading is measured in points from one baseline to the next. The leading value includes the point size of the typeface and the actual space between the lines. Thus, 10-point type with 12 points of leading really means two points of space between each line. This is written 10/12, and spoken “10 on 12.” Other common type size and leading combinations for print body text are 9/11, 11/13, and 12/15.

How Much Is Enough?

Bad leading makes your text harder to read because the eye has trouble locating the next line of type. Choosing an appropriate amount of leading depends on several variables:

The nature of the text. While text intended for continuous reading benefits from some breathing space, a short burst of advertising copy or a title might be more effective if the lines are tightly leaded.

Type size. As type size increases, you will want proportionally less leading. With display sizes, the same relative amount of space between the lines appears larger, so much so that it’s common to use negative leading for display type.

The width of the column. Increase leading as you increase column width, or measure. Increasing the leading anywhere from 0.5 point to 2 points improves readability by keeping the lines distinct and preventing the eye from dropping off to the line below or doubling back to reread the same line.

RELATIVE LEADING SIZES

A: Postive leading works OK for body text sizes.

B & C: As the type gets bigger, proportionally less leading is needed.

The width of the column gutters. Leading, like all type attributes, needs to work in harmony with everything else on the page. The width of the column gutters should be the same as the leading value or a multiple thereof. If the gutters are too small, there will be a tendency to read across the columns; too large and the separate columns will look unconnected.

The size of the word spaces. A general rule is that your leading should be wider than your word spaces to ensure that the eye moves along the line rather than down the lines. Justified type in narrow columns, such as in newspapers, may result in word spaces larger than the leading. This causes the eye to jump to the next line rather than to the next word. In such situations, extra leading ensures that the space between the lines is at least as wide as the space between the words. Better still, don’t set justified type in narrow columns.

LEADING AND JUSTIFIED TEXT

A: If leading is tight, especially with justified text on a narrow measure, there is the risk of having more space between the words than between the lines.

B: The gutter width is too big, and the columns lose their visual relationship to each other.

C: The gutter is too small, so that the two columns look almost like a single line.

The color of the background. We’re used to reading black type on white paper, so when we use the opposite, we’re guaranteed to get attention. However, reversed type tends to “sparkle,” making it harder to read. A slight increase in leading can compensate. In addition, if you’re working in print, avoid delicate serifs and consider using a heavier weight.

The characteristics of the typeface. Typefaces with larger x-heights are perceived as bigger than other typefaces at equivalent sizes. The lowercase letters are large relative to the size of the overall character, and thus require more leading.

Type that reverses out of a solid color benefits from increased leading (right) as well as an increase in weight.

Didone (also called Modern) typefaces that have a strong vertical stress, like Bodoni, guide the eye down the page rather than across the line. Adding more leading with these typefaces keeps the eye tracking horizontally rather than vertically.

Typefaces that combine a low x-height with particularly tall ascenders require special treatment. The low x-height begs suggest tighter leading, but tighter leading might cause the ascenders and descenders to collide. Much depends on the characters themselves. If you’re working on display type, rewording—if you have editorial license—might make all the difference. Let common sense prevail, and be open to the possibility that colliding ascenders and descenders might even look good in certain situations.

LEADING AND X-HEIGHT

Even though Raniscript has elongated ascenders and descenders, its low x-height means it looks good tightly leaded.

Leading Shortcuts

To tighten the leading of a selected range of text: Option+Up Arrow (Alt+Up Arrow)

To loosen the leading: Option+Down Arrow (Alt+Down Arrow)

The increment is determined in the Size/Leading field in the Units & Increments Preferences. To increase or decrease the leading value by five times this increment, press Cmd+Option+Up Arrow (Ctrl+Alt+Up Arrow) or Cmd+Option+Down Arrow (Ctrl+Alt+Down Arrow).

A leading gauge lets you measure the leading value on a printed piece.

TIP

A convenient rule of thumb for determining leading is to take the width of a column in picas and divide it by the size of the type, then round the result to the nearest half point. For example, 10-point type on a 24-pica measure yields a leading value of 2.4. This is rounded up to 2.5 and expressed as 12.5 (the lead added to the point size).

Typefaces with small x-heights appear to have more horizontal space between lines and thus require less leading.

Bold and Semibold typefaces benefit from extra leading to prevent the type color—the density of the letterforms as a block—from appearing too heavy.

Type in all caps requires less leading because the absence of descenders makes the lines appear farther apart.

Screen Leading (Line Height)

The W3C accessibility guidelines recommend a line height of 1.5 ems. While this is a good starting point, it’s not a figure that should be adhered to slavishly. Just as with print, optimal line height onscreen is a nuanced thing, and should factor in the size of the type, the length of the line, the x-height of the typeface, and the perceived preferences of the audience. While it’s broadly true that line height onscreen will be more than its equivalent in print (in part because line lengths onscreen tend to be longer), all of the factors discussed above are as applicable to screen typography as they are to print typography.

LEADING TYPE IN ALL CAPS

The same headline in all caps needs less leading because there are no descenders.